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Re: Divided Procat HD

Walter: Congratulations and thanks ! Your patience and persistence are helping us all.

Sandy: What does the wetting agent do, if it is applied in solution A ? Does it promote absorption of solution A into the film emulsion ?

If that is the case, would a longer pre-soak accomplish the same thing ?

Given that films have dyes which are removed in pre-soak, would it be helpful to perform more than one pre-soak, or to perform pre-soak with a large volume of water ?

What is the difference between a wetting agent (which breaks up surface tension in water), and something that changes the pH of the water ?

Walter - Are you sure the streaking in the first photo, isn't really a rare 'double twister" in the sky ? Also, could you share with us the Zone values for your photo ? I'm very interested in how things play out doing landscape photography. Did you use a filter for separation in the clouds ?

Walter,

Ken,

So far as I know the wetting agent does not promote absorption of Solution A into the emulsion. Rather, it releases the surface tension and allows Solution A to spread over the surface of the negative instead of pooling or streaking in one area as some liquids tend to do after they drain. If Solution A drains in streaks this could result in uneven development because Solution B would come into contact with uneven amounts of Solution A.

And no, I don't believe a longer pre-soak would accomplish the same thing as the wetting agent.

Re: Divided Procat HD

Ken

This is not a double twister, the negatives were exposed within 10 seconds of each other. I flipped the first negative on the JOBO reel on purpose just to see the difference. The shadows to the left of the shed were placed on zone III the brightest cloud was placed on XII I used no filter.

Re: Divided Procat HD

Those steaks are where the negative contacted or nearly contacted the ribs of the drum. Consequentaly the chemicals surged at the ribs leaving the steaks.

Originally Posted by walterb

Sandy
Another test with my divided pyro. Changed the dilution to 1:20 both A & B 600 ml ea
added 2ml of Kodak photo flo to the A. Developed both negatives at the same time 5 min ea., 1 min distilled water stop, 5 min tf4 fixer, 20 minutes wash distilled water.

I loaded one negative with the emulsion side to the outside on the JOBO reel, the other one was loaded correctly with the emulsion to the inside. The one loaded incorrectly shows streaking, the one loaded correctly show no blotches or streaking. I know it is only one negative but it appears that the photo flo has corrected the problem. This is the first time for me at least with no blotches.